Light Requirements - DIY

[cunniculus]

I'm afraid to even ask this question because I think it's kind of dumb, but I've been looking at AH Aquarium Lighting supply and trying to figure out how much light I need.

First question: For a planted/discus tank, 1.5W per gallon is a good rule of thumb, correct? Or is it 2W?

Second question. For a 75G tank, I would need ~112.5W (at 1.5W per gallon). Does this mean I need that Wattage to span the whole tank, or do I get two 22" 55W fixtures?

Sorry for the dumb question.....and thanks! ;D

[ronrca]

;) There is no thing as a dumb question so dont be afraid to ask!

Question #1
It is considered a guideline rather than a rule. The W/G depends on the type of light and depth of tank you have. There are low light plants, med and high light plants. 1.5W/G is around the mid mark! The best thing to do is research the types of plants you would like and match your lights. However, one thing to note is that higher lighting levels may result in the addition of C02 injection and increased fertilization.

Question #2
The lenght of the tube more or less depends on the length of your tank. You want to try to fit the longest tube in your canopy to get an even distribution of lighting across the whole tank. If you do not have enough w/g, just add a second tube!

;)

[ChloroPhil]

It all depends on the type of aquarium you want to keep. If you're willing to put a lot of time and effort into a single tank then by all means jack up the lighting and add some CO2. You'll have all the demand you could ever want from an aquarium. :)

On the other hand, if you're more interested in something a little easier on the time budget and a little more easy going go with lower lighting. It sounds like you're interested in this type of tank rather than a blow your socks off run the electric bill sky high system.

I'm going to make the assumption that you're more interested in the latter and would recommend using 48" T-12 NO fluorescent fixtures on your 75. You can get two two-bulb DIY fixtures for about 50.00 USD all-inclusive. That'll give you 160 watts which is just about 2.0 watts/gallon of mellow lighting and will do just fine for a discus tank with the more discus-friendly plants. It'll also keep the tank metabolism fairly slow and should help you keep a leg up on most algae types.

Best,
Phil

[cunniculus]

Thanks for all the replies and information, everyone!

Phil, I'm glad you chimed in because it seems you are the one to watch in planted tanks. Saw your award winning tank in old posts. I'm not worthy!

Anyway, I'm interested in something easy, yes, but I've been keeping fish long enough to realize that if it's worth doing, it's worth doing correctly. I've been looking into CO2 injection and good lighting and am willing to do the work and spend the money. My problem is that instead of doing, I just keep thinking and thinking.


So, given that I'm willing do do/spend a little more, would you recommend more lighting than 160W? Also, where would you get these 48" T-12 NO fluorescent fixtures? I didn't see any at the AH supply.

I've been looking into parts for a nice CO2 injection system. Tank, solenoid, regulator, pH controller, etc. I could go with a DIY setup but it sounds like they can be a real PITA and somewhat messy if you make mistakes.

In short, I've never kept discus or a planted tank. I'm interested in both and am willing to do the research/work, etc. I personally think a bare tank is a waste of space (no disrespect for those that disagree). I'm feeling a little overwhelmed with theory but don't want to jump in and make costly mistakes.

Thanks again for all your input, everyone! Keep it coming!

[ChloroPhil]

If you're willing to get all the doodads for the CO2 system then absolutely go for more light. My biggest problems are related to CO2 level imbalances and the resulting algae. An automated CO2 system will go far in averting many problems we face.

T-12 fluorescent lights are the regular fluorescents you see in office lighting fixtures. You can get fixtures, DIY or ready made, at any moderately sized hardware or home improvement store. If you're bent on using PC I would get ahsupply's 4x55 watt kit and run 2x55 and 2x36 bulbs. Even though the 2x55w fixture provides decent output, it doesn't have the coverage to do much of anything with it. It would also be very worthwhile to look into getting 4 2x40w T-12 "shoplight" fixtures at Lowe's or Home Depot. That'll give you moderate light levels across the whole tank. I've had some really nice aquascapes in a 55 using 2 2x40w fixtures.

Best,
Phil

[cunniculus]

Outstanding. Thanks for the information Phil. Proving that you're the guy to talk to. I'll check out those fixtures and continue on my quest for a good CO2 system.

I got an interesting email from AH supply in response to the same question I posted in this thread. Basically, they talked about me buying 4 22" light fixtures to cover the front and back of the aquarium. I thouht that was a little much, but I guess I should listen to the professionals.

Thanks again, everyone for the replies!

Damon